Methods: A total of 1,987 lymph nodes of 967 patients (666 males, 301 females; mean age: 62.1±11.9 years; range, 21 to 90 years) between May 2016 and July 2020 were retrospectively analyzed. The endobronchial ultrasound images of lymph nodes were evaluated according to the following criteria: size (short axis >1 cm), shape (round or oval), margin (distinct or indistinct), coagulation necrosis sign (present or absent), central hilar structure (present or absent) and echogenicity (homogeneous or heterogeneous). A scoring system was developed for predicting malignancy.

Results: A total of 765 (38.5%) of the lymph nodes were malignant. In the univariate analysis, size >1 cm, round shape, distinct margin, absence of central hilar structure, presence of coagulation necrosis sign, and heterogeneity were significant predictors of malignancy (p<0.001 for all). In the multivariate analysis, the main independent predictors were heterogeneity and presence of coagulation necrosis sign (odds ratio=5.9, 95% confidence interval: 4.2-8.2 vs. odds ratio=3.1 95% confidence interval: 2.2-4.5, respectively). A cut-off value for endobronchial ultrasound score of ?4 increased the malignancy risk 30 times with a sensitivity of 84.7%, and specificity of 84.5%.

Conclusion: Our study results show that endobronchial ultrasound scoring system with six criteria has a high sensitivity and specificity for predicting malignant lymph nodes.